/*
 * 重庆两江数智科技有限公司 - 官方网站样式表
 * 风格定位：大型高端企业、稳重、专业、精细，摒弃蓝色科技风和繁杂动画
 */

:root {
    /* 核心色彩系统 */
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #fafafc;
    --color-bg-dark: #121212;
    --color-bg-dark-secondary: #1a1a1a;
    
    --color-text-primary: #1d1d1f;
    --color-text-secondary: #515154;
    --color-text-muted: #86868b;
    --color-text-light: #f5f5f7;
    
    --color-accent: #c5a880; /* 高端香槟金/古铜金 */
    --color-accent-hover: #b08f62;
    --color-accent-light: #fcf9f5;
    
    --color-border: #e5e5ea;
    --color-border-dark: #2c2c2e;
    
    /* 字体系统 */
    --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    
    /* 间距与阴影 */
    --transition-smooth: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.02);
    --shadow-medium: 0 12px 30px rgba(0, 0, 0, 0.04);
}

/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition-smooth);
}

ul {
    list-style: none;
}

/* 布局版芯 */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 40px;
}

@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
}

/* 按钮组件 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 2px;
    transition: var(--transition-smooth);
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-primary {
    background-color: var(--color-text-primary);
    color: var(--color-bg-primary);
}

.btn-primary:hover {
    background-color: var(--color-accent);
}

.btn-outline {
    border-color: var(--color-border);
    color: var(--color-text-primary);
    background: transparent;
}

.btn-outline:hover {
    border-color: var(--color-text-primary);
    background-color: var(--color-text-primary);
    color: var(--color-bg-primary);
}

.btn-accent {
    background-color: var(--color-accent);
    color: white;
}

.btn-accent:hover {
    background-color: var(--color-accent-hover);
}

/* 导航栏 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: transparent;
    border-bottom: 1px solid transparent;
    transition: var(--transition-smooth);
}

.header.scrolled {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-subtle);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
    transition: var(--transition-smooth);
}

.header.scrolled .container {
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-svg {
    width: 32px;
    height: 32px;
    transition: var(--transition-smooth);
}

.logo:hover .logo-svg {
    transform: rotate(360deg);
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: 1px;
    color: #ffffff; /* 默认在深色背景上为高对比度白 */
    transition: var(--transition-smooth);
}

.header.scrolled .logo-text {
    color: var(--color-text-primary);
}

.nav-list {
    display: flex;
    gap: 32px;
}

.nav-link {
    font-size: 0.95rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.85); /* 默认在深色背景上为高光白色 */
    position: relative;
    padding: 6px 0;
    transition: var(--transition-smooth);
}

.header.scrolled .nav-link {
    color: var(--color-text-secondary);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: var(--transition-smooth);
}

.nav-link:hover {
    color: #ffffff;
}

.header.scrolled .nav-link:hover {
    color: var(--color-text-primary);
}

.nav-link:hover::after {
    width: 100%;
}

.header-btn {
    display: inline-block;
}

/* 移动端菜单按钮 */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: #ffffff; /* 默认在深色背景上为白色 */
    transition: var(--transition-smooth);
}

.header.scrolled .menu-toggle span {
    background-color: var(--color-text-primary);
}

@media (max-width: 992px) {
    .nav-list {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--color-bg-primary);
        flex-direction: column;
        padding: 20px 40px;
        gap: 20px;
        border-bottom: 1px solid var(--color-border);
        box-shadow: var(--shadow-medium);
    }
    
    .nav-list.active {
        display: flex;
    }
    
    .nav-list.active .nav-link {
        color: var(--color-text-secondary);
    }
    
    .nav-list.active .nav-link:hover {
        color: var(--color-text-primary);
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .header-btn {
        display: none;
    }
}

/* 巨幕 Hero */
.hero {
    position: relative;
    height: 100vh;
    min-height: 700px;
    display: flex;
    align-items: center;
    background-color: #121212;
    overflow: hidden;
    color: var(--color-text-light);
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.35;
    filter: grayscale(100%);
    transition: transform 10s ease-out;
}

.hero:hover .hero-bg {
    transform: scale(1.05);
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(18, 18, 18, 0.9) 30%, rgba(18, 18, 18, 0.4) 100%);
}

.hero .container {
    position: relative;
    z-index: 10;
}

.hero-content {
    max-width: 780px;
}

.hero-subtitle {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: 3px;
    color: var(--color-accent);
    text-transform: uppercase;
    margin-bottom: 24px;
    display: block;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.25;
    margin-bottom: 24px;
    letter-spacing: -1px;
}

.hero-title span {
    display: block;
    color: var(--color-bg-primary);
}

.hero-desc {
    font-size: 1.15rem;
    color: var(--color-text-muted);
    margin-bottom: 40px;
    max-width: 600px;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 16px;
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    .hero-actions {
        flex-direction: column;
    }
}

/* 通用板块设置 */
.section {
    padding: 120px 0;
}

.section-secondary {
    background-color: var(--color-bg-secondary);
}

.section-dark {
    background-color: var(--color-bg-dark);
    color: var(--color-text-light);
}

.section-header {
    margin-bottom: 80px;
    max-width: 640px;
}

.section-tag {
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 2px;
    color: var(--color-accent);
    text-transform: uppercase;
    margin-bottom: 16px;
    display: block;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 20px;
}

.section-desc {
    font-size: 1.05rem;
    color: var(--color-text-secondary);
}

.section-dark .section-desc {
    color: var(--color-text-muted);
}

/* 关于我们 */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    margin-top: 40px;
}

.about-feature-item h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--color-text-primary);
}

.about-feature-item p {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.about-img-wrapper {
    position: relative;
    border-left: 4px solid var(--color-accent);
    padding-left: 30px;
}

.about-img {
    filter: grayscale(100%);
    box-shadow: var(--shadow-medium);
}

@media (max-width: 992px) {
    .about-grid {
        grid-template-columns: 1fr;
        gap: 50px;
    }
}

/* 服务框架 */
.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.service-card {
    background-color: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    padding: 50px 40px;
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.service-card:hover {
    transform: translateY(-8px);
    border-color: var(--color-accent);
    box-shadow: var(--shadow-medium);
}

.service-num {
    font-size: 2rem;
    font-weight: 300;
    color: var(--color-accent);
    font-family: serif;
    margin-bottom: 30px;
}

.service-title {
    font-size: 1.35rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.service-desc {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: 30px;
}

.service-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-text-primary);
    display: flex;
    align-items: center;
    gap: 8px;
}

.service-link::after {
    content: '→';
    transition: var(--transition-smooth);
}

.service-card:hover .service-link::after {
    transform: translateX(5px);
}

@media (max-width: 992px) {
    .services-grid {
        grid-template-columns: 1fr;
    }
}

/* 核心产品 */
.products-filter {
    display: flex;
    gap: 16px;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.filter-btn {
    background: none;
    border: 1px solid var(--color-border);
    padding: 10px 24px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition-smooth);
    border-radius: 2px;
}

.filter-btn.active, .filter-btn:hover {
    background-color: var(--color-text-primary);
    color: var(--color-bg-primary);
    border-color: var(--color-text-primary);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.product-card {
    background-color: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    padding: 30px;
    transition: var(--transition-smooth);
    opacity: 1;
    transform: scale(1);
}

.product-card.hidden {
    display: none;
}

.product-tag {
    display: inline-block;
    padding: 4px 10px;
    background-color: var(--color-bg-secondary);
    color: var(--color-text-secondary);
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.product-name {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.product-desc {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

@media (max-width: 992px) {
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 576px) {
    .products-grid {
        grid-template-columns: 1fr;
    }
}

/* 核心技术能力 */
.tech-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.tech-list {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.tech-item {
    border-bottom: 1px solid var(--color-border-dark);
    padding-bottom: 20px;
}

.tech-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.tech-name {
    font-size: 1.15rem;
    font-weight: 600;
}

.tech-badge {
    font-size: 0.75rem;
    color: var(--color-accent);
    border: 1px solid var(--color-accent);
    padding: 2px 8px;
    border-radius: 2px;
}

.tech-desc {
    font-size: 0.9rem;
    color: var(--color-text-muted);
}

.tech-img {
    filter: grayscale(100%) contrast(1.1);
    border: 1px solid var(--color-border-dark);
    opacity: 0.8;
}

@media (max-width: 992px) {
    .tech-grid {
        grid-template-columns: 1fr;
        gap: 50px;
    }
}

/* 项目经验/案例 */
.case-list {
    display: flex;
    flex-direction: column;
    gap: 60px;
}

.case-item {
    display: grid;
    grid-template-columns: 4fr 5fr;
    gap: 60px;
    align-items: center;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 60px;
}

.case-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.case-item.reverse {
    grid-template-columns: 5fr 4fr;
}

.case-item.reverse .case-info {
    grid-column: 1;
}

.case-item.reverse .case-img-wrapper {
    grid-column: 2;
}

.case-img-wrapper {
    filter: grayscale(100%);
    overflow: hidden;
}

.case-img {
    transition: var(--transition-smooth);
}

.case-item:hover .case-img {
    transform: scale(1.03);
}

.case-category {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-accent);
    text-transform: uppercase;
    margin-bottom: 12px;
    display: block;
}

.case-title {
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.case-body {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: 24px;
}

.case-features {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.case-feature-item {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.case-feature-item::before {
    content: "■";
    color: var(--color-accent);
    font-size: 0.7rem;
    margin-top: 4px;
}

@media (max-width: 992px) {
    .case-item, .case-item.reverse {
        grid-template-columns: 1fr;
        gap: 30px;
        padding-bottom: 40px;
    }
    
    .case-item.reverse .case-img-wrapper {
        grid-column: 1;
    }
}

/* 核心方法与优势 */
.why-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
}

.steps-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.step-item {
    display: flex;
    gap: 24px;
}

.step-num {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-accent);
    line-height: 1;
    font-family: serif;
}

.step-title {
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: 6px;
}

.step-desc {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.methods-list {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

.method-card {
    background-color: var(--color-bg-secondary);
    padding: 30px;
    border-left: 3px solid var(--color-text-primary);
}

.method-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.method-desc {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

@media (max-width: 992px) {
    .why-grid {
        grid-template-columns: 1fr;
        gap: 60px;
    }
}

/* 页脚 Footer */
.footer {
    background-color: var(--color-bg-dark);
    color: var(--color-text-light);
    padding: 100px 0 50px 0;
    border-top: 1px solid var(--color-border-dark);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2.2fr 1fr 1fr 1.6fr;
    gap: 60px;
    margin-bottom: 60px;
}

.footer-brand .logo-text {
    color: white;
}

.footer-desc {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-top: 20px;
    line-height: 1.7;
}

.footer-title {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 24px;
    color: white;
    letter-spacing: 1.5px;
    position: relative;
    padding-bottom: 12px;
}

.footer-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 24px;
    height: 2px;
    background-color: var(--color-accent);
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-link {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    display: inline-block;
    transition: var(--transition-smooth);
}

.footer-link:hover {
    color: var(--color-accent);
    transform: translateX(4px);
}

.footer-contact {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.footer-contact-item {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    display: flex;
    align-items: flex-start;
    gap: 12px;
    line-height: 1.6;
}

.footer-contact-item span:first-child {
    color: var(--color-accent);
    flex-shrink: 0;
    margin-top: 2px;
}

.footer-bottom {
    border-top: 1px solid var(--color-border-dark);
    padding-top: 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.copyright {
    font-size: 0.85rem;
    color: var(--color-text-muted);
}

.copyright a {
    color: var(--color-text-muted);
    text-decoration: none;
}

.copyright a:hover {
    color: var(--color-accent);
}

.footer-bottom-links {
    display: flex;
    gap: 24px;
}

@media (max-width: 992px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 40px;
    }
}

@media (max-width: 576px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }
    .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* 动效/优雅入场动画 */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}